Polymorphisms in toll-like receptor (TLR) 1, 4, 9 and SLC11A1 genes and their association with paratuberculosis susceptibility in Holstein and indigenous crossbred cattle in Turkey

Mycobacterium avium subsp. paratuberculosis (MAP) causes major problem in a wide range of animal species. In ruminant livestock including cattle, it causes a chronic disease called Johne's disease, or paratuberculosis (pTB) which is currently considered as potential zoonosis, causing Crohn's disease in humans. MAP infection susceptibility is suspected to be controlled by host genetics. Thus, selecting individuals according to their genetic structure could help to obtain bovine populations that are increasingly resistant to MAP infection. The aim of the present work was to investigate the association between toll-like receptor (TLR) 1 (+1380 G/A), TLR1 (+1446 C/A), TLR4 (+10 C/T), TLR9 (+1310 G/A) and solute carrier family 11 member 1 (SLC11A1) (+1066 C/G) mutations and MAP infection status in 813 cattle comprising East Anatolian Red crossbred, Anatolian Black crossbred and Holstein breed. TLR1 (+1380 G/A) mutation showed an association with bovine MAP (P-0.1666670.05). For the TLR1 (+1380 G/A) locus, the odds ratio for AG and AA genotypes versus GG genotypes were 2.31 (1.24-4.30; 95% confidence interval (CI)) and 0<0.001 (<0.001 to >999.999; 95% CI) which indicated that a proportion of AG homozygote was significantly higher in pTB-affected animals as compared with the control. General linear model analysis demonstrated higher MAP antibody response in TLR1 (+1380 AG) genotype as compared with TLR1 (+1380 GG) (P-0.1666670.0001). Present findings suggest that selection against TLR1 (+1380 G/A) may reduce the risk of pTB in bovine herds.